1. Field of the Invention
The present invention relates to a three-way solenoid valve, and more particularly, to a three-way solenoid valve that is suitable to switch a refrigerant flow passage in a heat pump device of, for example, a heating and cooling system and the like.
2. Description of the Related Art
In the past, a three-way solenoid valve disclosed in JP 2012-002282 A has been known as this kind of a three-way solenoid valve.
As illustrated in FIGS. 3 and 4, the three-way solenoid valve 1′ in the related art includes: a valve body 2′ that includes one inlet 2a′, first and second outlets 2b′ and 2c′, and valve chests 2d′ and 2e′; first and second valve seats 3′ and 4′ that are positioned in the valve body 2′; first and second valve elements 6′ and 7′ that approach and are separated from these valve seats 3′ and 4′ and allow the inlet 2a′ and the outlets 2b′ and 2c′ to communicate with each other; actuating rods 9′ (9a′, 9b′) as a plurality of actuating members that are interposed between both the valve elements 6′ and 7′ and come into contact with both the valve elements 6′ and 7′ at end portions thereof; a lid 11′ that closes a lower opening of the valve body 2′; a coil spring 12′ that is interposed between the lid 11′ and the second valve element 7′ and biases the second valve element 7′ toward the second valve seat 4′; a valve holder 15′ that approaches and is separated from the first valve element 6′ at a lower end portion thereof; an electromagnetic coil assembly 14′ that moves a plunger 13′ integrated with the valve holder 15′ up and down; and the like.
When current is not applied to an electromagnetic coil 14a′ of the electromagnetic coil assembly 14′, as illustrated in FIG. 3, the second valve element 7′ is biased upward by the coil spring 12′ and is seated on the second valve seat 4′, and the first valve element 6′ is moved up through the second valve element 7′ and the actuating rods 9′ and is separated from the valve seat 3′. When fluid is made to flow from the inlet 2a′, differential pressure is generated on the upper and lower sides of the first valve element 6′ and the first valve element 6′ is biased upward. Accordingly, fluid is made to flow to the first outlet 2b′ from the inlet 2a′ through the valve chest 2d′. 
Further, when current is applied to the electromagnetic coil 14a′ in a state in which fluid is made to flow from the inlet 2a′, the plunger 13′ is attracted to an attractor 16′ and is moved down as illustrated in FIG. 4. Accordingly, the valve holder 15′ is also moved down. Immediately after the valve holder 15′ is moved down, a lower end portion of the valve holder 15′ comes into contact with an upper end portion of a through hole 6a′ of the first valve element 6′ and closes an upper opening of the through hole 6a′. Accordingly, differential pressure is removed on the upper and lower sides of the first valve element 6′ and the first valve element 6′ is seated on the valve seat 3′ by the pressing of the valve holder 15′. The plurality of actuating rods 9′ are also moved down with the movement of the plunger 13′, the valve holder 15′, and the first valve element 6′. Accordingly, the second valve element 7′ is also moved down and is separated from the second valve seat 4′. Therefore, fluid is made to flow to the second outlet 2c′ from the inlet 2a′ through the valve chest 2e′. 